Method and apparatus for controlling a quiet zone for wireless units

ABSTRACT

In one embodiment, a device in an IP-based cellular wireless communication system includes a monitoring arrangement and a sender arrangement. The monitoring arrangement arranged to detect a location of a cellular phone device with respect to an area of restricted access. The location of the cellular phone device with respect to the area of restricted access is detected in part by determining when a preset period of time has elapsed. The sender is arranged to send a first message including information associated with the cellular phone device when the location of the cellular phone device with respect to the area of restricted access is detected. A method for operating the device is also disclosed.

RELATED APPLICATIONS

This patent application is a divisional of U.S. patent application Ser.No. 11/126,838, filed May 11, 2005, which is a continuation of U.S.patent application Ser. No. 09/803,424, filed Mar. 8, 2001 (U.S. Pat.No. 6,907,254), which are incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION

The present invention relates to wireless units including cellulartelephones with IP capability. In particular, it relates to providingcontrol over IP cellular phone units within a physical area such as atheater or restaurant.

The use of cellular telephones using various protocols including CDMAand GSM, as well as the use of other cellular devices such as PCSdevices, is ubiquitous. These cellular units can cause unwelcome soundsin shared spaces causing annoyance. For example, phones may ring duringa theater performance or persons may converse on a cell phone at a quietrestaurant.

Although sometimes a venue requests cellular phone users to turn offtheir phones while inside the space, such as by posting signs or makingan announcement prior to a performance, this is not always effective.Sometimes the cell phone user wishes to comply with the request butforgets to turn off the phone, and sometimes the cell phone user ignoresthe request. Therefore, it is desirable for the operator of arestaurant, theater, or other space to obtain control over cellularunits within their space.

Major initiatives have been taken by various entities, including theInternational Telecommunication Union (ITU), to push forward universalmobile systems, called third generation or 3G mobile systems. Standardsfor third generation wireless include W-CDMA and IMT-2000, which is astandard adopted by the ITU. IMT-2000 encompasses a variety of mobile orfixed terminals (cellular phone units) that can provide phone service,web access, video teleconferencing, and other services. The mobileterminals are linked by one or more radio links to varioustelecommunications services and networks (e.g. PSTN/ISDN/IP) and otherservices. Information about IMT-2000 is available from various sources,including www.itu.org, www.3gpp.org, and www.3gpp2.org.

An overall architecture for a wireless IP network architecture based onvarious protocols has been described in the Internet Engineering TaskForce's Wireless IP Network Architecture based on IETF Protocols (TomHiller, ed.), IETF TR45.6 Ballot (Feb. 4, 2000), which is herebyincorporated by reference. This document describes the packet dataservices to be provided, and sets forth the packet data systemarchitecture for a third generation wireless system based on IMT-2000.The described system is designed to have general capabilities that matchthose outlined in the ITU IMT-2000 requirements document Q.1701. IETFprotocols are employed wherever possible to minimize the number of newprotocols required.

An example wireless IP network architecture is shown in FIG. 1A. A useruses mobile station 10 to connect to Radio Network 20 (also called aRadio Access Network, or “RAN”) via an air interface, and through theRadio Network 20, gains access to a service provider network. Only oneservice provider network may be accessed by the mobile station 10 at atime, and the service provider network may be the user's home accessprovider or if the user is roaming, the visited access provider network.Existing air interface procedures are used for access mobilitymanagement, including interactions with Visitor Location Registers (VLR)32 and Home Location Registers (HLR) 34. The HLR 34 stores accessservice profiles that contain information about access serviceparameters, which are cached in the VLR 32 while the mobile station 10is registered in the service provider access network. An open interface,known as the R-P interface, is defined between the Radio Network 20 andthe Packet Data Serving Node (PDSN) 30. The PDSN 30 interacts with thelocal or visited AAA (Authentication, Authorization, and Accounting)server 36 and with other servers using IP protocols within the IPNetwork 38.

An example Radio Network 20 is shown in FIG. 1B. It can include multiplebase stations 21 that communicate with a switching center 22, or othercentral facility, and can for example be a CDMA2000 RAN. Each of thebase stations 21 covers a geographic area as known in the art ofcellular communications. A mobile station 10, which can be a cellulartelephone device/personal communication device/mobile terminal, canreceive communications from, and transmit communication to, a basestation 21.

The coming availability of third generation mobile terminals with theirmultifunction capabilities and enhanced ease of roaming will increasethe presence of such multifunction personal communications devices ineveryday life. The attendant intrusions into shared spaces will alsoincrease annoyances such as those caused by cell phones ringing, videoteleconferences occurring, the web being surfed, games being played overthe web, etc.

Accordingly, it would be desirable to provide a way to restrict use ofthird generation mobile terminals, including those with cell phonecapability, in designated spaces.

SUMMARY OF THE INVENTION

In an IP-based cellular wireless communication system, embodiments ofthe invention provide systems and methods for spatially controllingcellular phone usage. Entry of a cellular phone device into an area ofrestricted phone access (“quiet zone”) is detected and an IP messageidentifying the phone sent to a central facility. In one embodiment, anIP message is sent to the phone causing it to change behavior, forexample turning off the volume on the ringer. Alternatively, the centralfacility can process an incoming call for a phone that is determined tobe in a quiet zone to reduce intrusion in the quiet zone; for example,it can send the call to a phone mailbox or give the caller a busysignal.

In one embodiment, an IP message that includes information about whethera cellular phone device is in an area of restricted service access isreceived at a central facility. The message includes an identifierassociated with the cellular phone device. Data associated with thecellular phone device is updated. The data can include a table of hushedphones maintained at the central facility, or can include a statusassociated with the cellular phone in a Home Location Register (HLR) orVisitor Location Register (VLR). In one embodiment, the central facilitythen sends an IP message that can include a hushing command, to thecellular phone device.

In one embodiment, when a call for a cellular phone device is receivedat the central facility, it is determined whether the cellular phonedevice is in an area of restricted service access (quiet zone). If not,the call is processed. If the cellular phone device is in an area ofrestricted service, the call is processed including special quiet zoneprocessing. The special quiet zone processing can include sending thecall to a phone mailbox or giving a busy signal to the caller.

In one embodiment, a method of operating a quiet zone controller in anIP based cellular system is provided. A cellular phone device isdetected entering an area, the cellular phone device being serviced by aservice provider control point, and sends an IP message to the serviceprovider control point, the IP message including an identifierassociated with the cellular phone device. In an embodiment, thecellular phone device is monitored. When it is determined that thecellular phone device has left the area, a second IP message is sent toa service provider control point. In an embodiment, a list of cellularphone devices in the area can be maintained locally if desired. In anembodiment, an IP message is sent to the cellular phone device thatincludes notification that the cellular phone device has entered a quietzone.

In an embodiment, a cellular phone device that is capable of varying itsbehavior in response to a hushing message is provided. The hushingmessage includes IP packets. In one embodiment, the phone goes into aquiet mode in response to the hushing message. In an embodiment, thehushing message can include an HTTP web page that includes selectablebuttons. The cellular phone device changes its behavior according to aset of selectable buttons that is selected by an operator of thecellular phone device.

In one embodiment, an apparatus for spatially controlling cellular phoneaccess in an IP based wireless communication system is provided. Theapparatus includes a processing system and a memory storing code foroperating said processing system. The code includes code that receivesan IP message at a central facility, the message including informationabout whether a cellular phone device is in an area of restrictedservice access and an identifier associated with the cellular phonedevice; and code that updates data associated with the cellular phonedevice in response to receiving the IP message.

In one embodiment, a computer program product for spatially controllingcellular phone access in an IP-based cellular wireless communicationsystem is provided. The computer program product comprises computer codethat receives an IP message at a central facility, the message includinginformation about whether a cellular phone device is in an area ofrestricted service access and an identifier associated with the cellularphone device; computer code that updates data associated with thecellular phone device in response to receiving the IP message; and acomputer readable medium that stores the computer code.

In yet another embodiment a computer program product for operating aquiet zone controller in an IP-based cellular wireless communicationsystem is provided. The computer program product comprises computer codethat detects a cellular phone device entering an area, the cellularphone device being serviced by a service provider control point;computer code that sends an IP message to the service provider controlpoint, the IP message including an identifier associated with thecellular phone device; and a computer readable medium that stores thecomputer code.

The cellular phone device can be a third generation mobile terminal orother IP capable communication device, including IP capable cellularphones.

A further understanding of the nature and advantages of the inventionsherein may be realized by reference to the remaining portions of thespecification and the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a simplified model of the packet data system architecture fora third generation wireless system based on IMT-2000.

FIG. 1B is a diagram of an example radio access network.

FIG. 2 illustrates a system block diagram of an example computer systemthat can be utilized to execute the software of an embodiment of theinvention.

FIG. 3A illustrates an embodiment of the invention.

FIG. 3B illustrates a sample wireless multi-function communicationdevice with phone capability.

FIG. 4 is a top level flow chart describing the process of providing aquiet zone service.

FIG. 5 is a process flow diagram of an overview of maintaining a quietzone in a preferred embodiment.

FIG. 6A is a process flow diagram of hushing a phone.

FIG. 6B is a top level diagram of entering/exiting hush mode.

FIGS. 7A-C are process flow diagrams of maintaining information aboutphones in a quiet zone and updating the status of a phone.

FIGS. 8A-C are process flow diagrams of processing a call at a centralfacility and determining whether a phone is in a quiet zone.

FIG. 9 is a process flow diagram of processing a call with simultaneousupdating of a phone status.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Embodiments of the invention are described below with reference tospecific processing systems and methods. However, embodiments of theinvention can be implemented in various ways. For example, aspects ofthe invention can be implemented in software or hardware or usingspecial purpose processors or by any other known mechanism. Therefore,the description of the embodiments that follows is for purposes ofillustration and not limitation.

FIG. 2 shows a system block diagram of a computer system 200 that can beused to execute software implementing a portion of a method of anembodiment of the invention. For example the computer system 200 can runsoftware used in a quiet zone controller 340 (described below) or canrun software at switching center 22. Computer system 200 can includesubsystems such as a central processor 251, system memory 253, fixedstorage 255 (e.g., hard drive), removable storage 257 (e.g., CD-ROMdrive), and network interface 265.

System memory 253, fixed storage 255, and removable storage 257 can beutilized to store and retrieve software programs incorporating computercode that implements the invention, data for use with the invention, andthe like. Although CD-ROM 15 is shown as an exemplary computer readablestorage medium, other computer readable storage media including floppydisk, tape, flash memory, system memory, and hard drive can be utilized.Additionally, a data signal embodied in a carrier wave (e.g., in anetwork including the Internet) can be the computer readable storagemedium.

The system bus architecture of computer system 200 is represented byarrows 267. However, these arrows are illustrative of anyinterconnection scheme serving to link the subsystems. For example, alocal bus could be utilized to connect the central processor to thesystem memory and display adapter. Computer system 200 shown in FIG. 2is but an example of a computer system suitable for use with theinvention. Other computer architectures having different configurationsof subsystems including additional or fewer subsystems can also beutilized.

FIG. 3A shows an embodiment of the invention. A venue 300, for example amovie theater or restaurant, can accommodate human patrons 320. One ormore patrons 320 can have a mobile communication device 330, with IPcapability, such as a cellular phone device with IP capability or athird generation cellular device with web access, phone, and videoteleconferencing capability. The device 330 can communicate with thetelephone system or Internet or other service provider through a radioaccess network, such as the setup shown in FIG. 1.

In a preferred embodiment a quiet zone controller 340 communicatesthrough the radio access network with one or more services. The quietzone controller monitors an area of interest in the venue for thepresence of mobile communication devices. This can be done by monitoringtransmission in the area, for example, monitoring autonomousregistration information. (As known in the art, a phone on being turnedon tunes into the overhead signal sent by the system and registers withthe mobile telephone switching office (MTSO), which records locationinformation in the HLR database (or VLR database if the phone isroaming). The system periodically, e.g. every 5-15 minutes, requests thephone to re-identify itself, and if the phone is turned on it respondsby transmitting identification information, which can include itselectronic serial number (ESN) and mobile identification number (MIN);this process is called “autonomous registration”. Using autonomousregistration, the system can monitor approximately where the phone is inthe network, which allows it to limit the number of cells/base stationsto be contacted to reach the phone.)

The quiet zone controller preferably communicates with a centralfacility, such as switching facility 22 by transmitting messages to abase station 21 that relays the message to the switching facility 22,but any known method of communication can be used. The central facilitycan be any entity that controls access to the base stations or routescalls, and can be a facility that is analogous to the Mobile TelephoneSwitching Office (MTSO) or Mobile Switching Center (MSC) in secondgeneration systems.

In an alternative structure according to the present invention, quietzone controller 340 is associated with a particular cell that has beenset up inside a building to assure cellphone coverage within thebuilding or at a high subscriber density location. This makes it easierto intercept registration information.

FIG. 3B is an illustration of an example mobile communication device 390that has phone, web access, email, and videoconference capability. Themobile communication device 390 preferably has the ability to beelectronically switched to different modes of operation, for example toa mode where the phone vibrates instead of rings.

FIG. 4 is a top level process flow diagram of providing a quiet zoneservice. At a step 410 a quiet zone subscriber account is created. Thesubscriber account can include information such as billing address andpayment plan as well as details of the quiet zone such as hours ofoperation, e.g. for a theater it might be desired for the quiet zone tobe active only during a performance. It can also include the physicalparameters of the quiet zone, e.g. the latitude and longitude ofendpoints of line segments making up a quiet zone. The physicalparameters of the quiet zone can be used if it is desired that whether aphone is in a quiet zone be determined by using GPS to locate a phonehaving a GPS transmitter, in which case whether the phone is in a quietzone can be determined by comparing the phone's location with one ormore parameters of the quiet zone, and a quiet zone controller 340 neednot be deployed in the quiet zone. Preferably a portion of the quietzone subscriber account information is available at the centralfacility/switching center 22 that communicates with the base station 21whose geographic coverage includes the quiet zone.

At a step 420 phone calls to phones in a quiet zone are blocked orotherwise processed to reduce disruption to a quiet zone, as describedbelow. At a step 430 revenue is collected from the quiet zonesubscriber.

FIG. 5 is a process flow diagram of an overview of maintaining a quietzone in a preferred embodiment. A quiet zone controller monitors thequiet zone for cellular devices at a step 510. At a step 520 the quietzone controller keeps the switching center 22 informed of what cellulardevices are in the quiet zone. This can be done by informing theswitching center 22 whenever a new cellular device is detected in thequiet zone and whenever a cellular device is determined to have left thequiet zone. Any known methods can be used to determine whether a devicehas left the quiet zone; for example, the device can be deemed to haveleft the quiet zone after a preset period of time has passed withoutdetecting a signal, such as autonomous registration, from the phone.Note that if a phone has been turned off, it is acceptable to deem it ashaving left the quiet zone, as it will not function when off. Thecentral facility enforces the quiet zone at a step 530, as describedbelow.

One method of enforcing the quiet zone is to put the phones in the quietzone into a quiet mode. The quiet mode of a cellular device can includefor example turning the power off, setting a ringer volume to zero, orswitching from a ring mode to a vibrate mode. FIG. 6A shows a processflow diagram of enforcing a quiet zone by changing the mode of operationof the cellular device. At a step 610, a central facility receives an IPmessage that includes information that a phone has entered a quiet zone.An identifier that identifies the phone is included in the message. Theidentifier for example can be the phone's mobile identification number(MIN), or the ESN or both. Preferably the message also identifies thequiet zone. The central facility preferably is a switching center.Preferably the IP message is one that has been sent by a quiet zonecontroller and has been relayed through the radio access network to thecentral facility. At a step 620, the central facility sends a hushingcommand to the phone, preferably by sending an IP message the basestation, which relays it to the phone. The hushing command causes thephone to go into a quiet mode and can be configurable, for example itcan be a command for the phone to turn itself off.

FIG. 6B is a top level diagram of entering/exiting hush mode. At a step630 a hush packet is received. At a step 640 a hush mode is entered. Ina preferred embodiment, the user is able to configure his phone's hushmode. For example, the user can use a web application that offers aselection of selectable options to configure hush mode to have the phonevibrate and not ring; alternatively or additionally there can be aphysical switch on the phone that can be manually moved to select howthe phone will respond when in hush mode, e.g. with three settings onthe switch: send message to mailbox, give a busy signal, or vibrate.

At a step 650 the phone operates in hush mode. At a decision step 660,it is decided whether an anti-hush packet has been received. If ananti-hush packet has not been received, the phone continues to operatein hush mode. If an anti-hush packet has been received, the phone exitshush mode at a step 670. In a preferred embodiment, exiting hush modeincludes returning to the mode of operation the phone was in prior toreceiving a hush packet. In an alternate embodiment, exiting hush modecan include resetting the phone to a default setting. Also, hush modemay be exited automatically upon movement to a different cell.

It should be noted that according to the present invention, a quiet modeor hush mode may be required in a given zone for reasons other thanpreventing audible disturbance to those in the vicinity. For example,the quiet zone may be defined so that phones in the zone will have theirtransmitters turned off for the purpose of preventing RF interference tosensitive devices. This embodiment will provide protection in hospitals,airplanes, and other areas where cellphone transmitters should be keptoff for safety reasons.

An alternative way of enforcing a quiet zone is to keep track of whichphones are in quiet zones, and process calls for these phones in a waythat minimizes disturbances in the quiet zone. A process flow diagramfor maintaining information about phones in quiet zones is shown in FIG.7A. An IP message including an identifier associated with a phone isreceived at a central facility, which preferably is a switching center22, at a step 710. Preferably the IP message is sent by a quiet zonecontroller 340 in a quiet zone, and the phone has been detected in thequiet zone. At a step 720 the status of the phone is updated at thecentral facility. The status of the phone can be updated by adding theidentifier of the phone to a list of hushed phones (phones in quietzones), as shown in step 750 in FIG. 7B. Alternatively, a hush statusfield can be maintained in the visitor location register (VLR) or homelocation register (HLR) of the phone as shown in step 751 of FIG. 7C.The value of the field can be varied depending on parameters associatedwith the quiet zone the phone is in. For example, in some quiet zonesthe phone may be completely disabled (no incoming or outgoing calls),whereas in other quiet zones partial services can be maintained (forexample, outgoing calls only are allowed, or only emergency calls areallowed such as 911 calls or operator breakthroughs).

A process flow diagram for processing calls is shown in FIG. 8A. At astep 810 an incoming call for a phone is received at a central facility.At a decision step 820 it is determined whether the phone is in a quietzone. If the phone is not in a quiet zone, the process proceeds along aNO path to a step 830 where the call is processed using standardprocedures. If result of decision step 820 is that the phone is in aquiet zone, the process proceeds to a step 840 where the call isprocessed using a hush, or quiet zone, procedure. The quiet zoneprocedure can include for example giving the caller a busy signal orsending the caller to a voice mailbox.

FIGS. 8B and 8C show two ways for it to be determined whether the phoneis in a quiet zone. A list of phones that are in quiet zones can bechecked for the phone as shown in step 851 of FIG. 8B. Alternatively, ahush status can be checked in the visitor location register (if thephone is visiting/roaming) or the home location register of the phone,as shown in step 852 of FIG. 8C.

FIG. 9 shows an alternative method of processing a call that includessimultaneous updating of the quiet zone information. At a step 910 acall for a phone is received at a central facility. At a step 920 it ischecked whether the phone is in a quiet zone, either by checking a listor by checking a status field in a VLR or HLR. If the phone's status ishushed, the call is processed as a quiet zone call. If the phone is nothushed, then base stations are commanded to page the phone at a step940. An ACK will be received from the phone via a base station as knownin the art at a step 950. The process waits for a preset period of timeto pass at a step 960. If a quiet zone update for the phone has not beenreceived by the central facility after the preset period of time haspassed, the call is processed with standard processing. If, before theexpiration of the preset period, a quiet zone update for the phone isreceived by the central facility indicating the phone is in a quietzone, the call is processed as a quiet zone call as described withregard to FIG. 8.

In an alternate embodiment, the quiet zone controller need notcommunicate with a central facility, but can merely send an IP messageto phones detected in the quiet zone. The IP message can, for example bea request to the phone user to turn the phone off, or it can be amessage with a selectable buttons that can be selected by the user tochange the mode of the phone, for example to turn the ringer off.

While the above is a complete description of preferred embodiments ofthe invention, various alternatives, modifications, and equivalents canbe used. It should be evident that the invention is equally applicableby making appropriate modifications to the embodiments described above.For example, the flowcharts are exemplary embodiments but steps may beadded, deleted, combined, and reordered without departing from thespirit and scope of the invention. Therefore, the above descriptionshould not be taken as limiting the scope of the invention that isdefined by the metes and bounds of the appended claims along with theirfull scope of equivalents.

For example, referring to FIG. 9, steps 920-930 can be eliminated, andthe quiet zone controller can be programmed to always send an updatewhen it detects an ACK being sent by a phone in the quiet zone. Or, anIP message can be sent to a phone in a quiet zone with selectablebuttons allowing the user to change mode of the phone or additionally oralternatively to select the processing of calls, for example the usercan choose to send all calls to a mailbox, give a busy signal, turn thephone off etc.

The foregoing describes embodiments of an invention that can providecontrol over IP cellular telephones in certain zones. The features overwhich control is exerted are configurable.

1. In an IP-based cellular wireless communication system, a devicecomprising: a monitoring arrangement, the monitoring arrangement beingarranged to detect a location of a cellular phone device with respect toan area of restricted access, wherein the location of the cellular phonedevice with respect to the area of restricted access is detected in partby determining when a preset period of time has elapsed; and a senderarrangement, the sender being arranged to send a first message includinginformation associated with the cellular phone device when the locationof the cellular phone device with respect to the area of restrictedaccess is detected; wherein the location of the cellular phone devicewith respect to the area of restricted access represents a change fromthe cellular phone device being in the area of restricted access to thecellular phone device being out of the area of restricted access, thechange being detected when the preset period of time has elapsed withouta signal from the cellular phone device being detected by the monitoringarrangement.
 2. The device of claim 1 further including: a memoryarrangement, the memory arrangement being arranged to maintain a list ofcellular phone devices in the area of restricted access.
 3. The deviceof claim 1 wherein said information comprises an identifier of thecellular phone device and identification of the area of restrictedservice access.
 4. The device of claim 1 wherein the first message is anIP message including an identifier associated with the cellular phonedevice.
 5. The device of claim 4 wherein the IP message is received froma quiet zone controller.
 6. The device of claim 4 wherein the identifieris a Mobile Identification Number.
 7. The device of claim 1 wherein thesender arrangement is arranged to send a second message, the secondmessage being arranged to be sent to the cellular phone device when themonitoring arrangement detects that the cellular phone device hasentered the area of restricted access.
 8. The device of claim 7 whereinthe second message includes an HTTP web page with selectable buttonsassociated with hush options.
 9. The device of claim 7 wherein thesecond message includes a hushing command.
 10. In an IP-based cellularwireless communication system, a device comprising: means for detectinga location of a cellular phone device with respect to an area ofrestricted access, wherein the location of the cellular phone devicewith respect to the area of restricted access is detected in part bydetermining when a preset period of time has elapsed; and means forsending a first message including information associated with thecellular phone device when the location of the cellular phone devicewith respect to the area of restricted access is detected wherein thelocation of the cellular phone device with respect to the area ofrestricted access represents a change from the cellular phone devicebeing in the area of restricted access to the cellular phone devicebeing out of the area of restricted access, the change being detectedwhen the preset period of time has elapsed without a signal from thecellular phone device being detected by the monitoring arrangement. 11.The device of claim 10 wherein the first message is an IP messageincluding an identifier associated with the cellular phone device. 12.The device of claim 10 further including means for sending a secondmessage, the second message being arranged to be sent to the cellularphone device when the means for detecting detects that the cellularphone device has entered the area of restricted access.
 13. The deviceof claim 10 further including: means for maintaining a list of cellularphone devices in the area of restricted access.
 14. The device of claim10 wherein said information comprises an identifier of the cellularphone device and identification of the area of restricted serviceaccess.
 15. In an IP-based cellular wireless communication system, amethod of operating a device comprising: detecting whether a cellularphone device is within an area, the cellular phone device being servicedby a service provider control point, wherein detecting whether thecellular phone device is within the area includes determining when apreset period of time has elapsed; and sending a first message to theservice provider control point when the preset period of time haselapsed, the first message including information associated with thecellular phone device when the location of the cellular phone devicewith respect to the area is detected; wherein the location of thecellular phone device with respect to the area of restricted accessrepresents a change from the cellular phone device being in the area ofrestricted access to the cellular phone device being out of the area ofrestricted access, and detecting whether the cellular phone device iswithin the area includes detecting the change when the preset period oftime has elapsed without a signal from the cellular phone device beingdetected.
 16. The method of claim 15 wherein the first message is an IPmessage arranged to be sent to the service provider control pointthrough a radio access network, the IP message including an identifierassociated with the cellular phone device.
 17. The method of claim 15further including: maintaining a list of cellular phone devices in thearea of restricted access.
 18. The method of claim 15 wherein saidinformation comprises an identifier of the cellular phone device andidentification of the area.
 19. The method of claim 15 further includingsending a second message, the second message being sent to the cellularphone device when the cellular phone device is detected as entering thearea.
 20. The method of claim 19 wherein the second message is a hushcommand.